One type of ketone flooding the brain is beta-hydroxybutyrate, or BHB. According to a paper published in February in Nature Reviews Neuroscience, BHB stimulates memory, learning and the cellular housekeeping process of autophagy in mice. BHB also triggers neurons, including those in the hippocampus, a memory center in the brain, to release what’s called brain-derived neurotrophic factor, or BDNF, a protein that is important for learning, memory and improved mood. CR doesn’t generate these levels of ketones because glucose stores are never empty.
Intermittent fasting (intermittent energy restriction or intermittent calorie restriction) is an umbrella term for various eating protocols that cycle between a period of fasting and non-fasting over a defined period. Intermittent fasting is under preliminary research to assess if it can produce weight loss comparable to long-term calorie restriction.
Fasting is always practiced prior to surgery or other procedures that require general anesthesia because of the risk of pulmonary aspiration of gastric contents after induction of anesthesia (i.e., vomiting and inhaling the vomit, causing life-threatening aspiration pneumonia). Additionally, certain medical tests, such as cholesterol testing (lipid panel) or certain blood glucose measurements require fasting for several hours so that a baseline can be established. In the case of a lipid panel, failure to fast for a full 12 hours (including vitamins) will guarantee an elevated triglyceride measurement.